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Re: lathe question

Posted: Sat Jun 01, 2024 7:45 am
by Rick Denney
TxTx wrote: Tue May 28, 2024 11:19 pm
Kingconn wrote: Sun May 26, 2024 7:30 am A South Bend 10" with a 5c collet closer is a very handy machine.
I’ve never used a lathe with collets - only three, four, and six-jawed chucks - would think the attraction is if you’re doing a lot of work with the same diameter round stock. And perhaps more rigid mounting in the headstock.

Genuinely curious.

Eric
Collets have the advantage of runout in tenths (a tenth is 0.0001”) instead of thousandths. A four-jaw chuck can be dialed in, but a collet is instantly repeatable. And it will hold an end mill tightly if you use a milling attachment.

The South Bend 9 came in three versions—the 9a with no power feed, the 9b with power feed and change gears, and the 9c with power feed, change gears, and half-nuts for thread cutting.

The light 10 is another variation of the 9. The heavy 10 is the smallest of the S-series light industrial lathes that include the 10, 13, 14-1/2, 16, and 16-24. Bed lengths varied. Tool room versions came with collet closers and taper attachments (and higher precision spindles and feed screws), and standard “engine” lathes came with chucks. Of course, chucks were usually added to tool room lathes.

Any South Bend is heavy enough to justify the swing it supports. The same cannot be said for most hobbyist lathes like the Atlas. But SB lathes are belt-driven, and don’t have the power of more serious industrial lathes in the 13-16” range that had gear-driven headstocks. That said, they are powerful enough for anything any of us are likely to do.

Old lathes will need care and feeding. Ask me how I know. And tooling isn’t cheap though sticking with high-speed steel tooling (and learning how to grind and sharpen it) is the cheapest and best for most hobbyist machining, particularly with belt-driven machines.

Rick “SB 14-1/2 Toolroom ca. 1946” Denney

Re: lathe question

Posted: Sat Jun 01, 2024 2:41 pm
by bloke
You can probably convert a B flat tuba to a C tuba by mounting it on a lathe and taking off one 9th of the diameter, but you really need to get it centered and balanced properly prior to turning it on and going through the procedure.

I would think that a collet would be advisable, but it needs to be an extremely customized one.